For 40 years a huge mountain of stones and two stumps was all that was left of the Frauenkirche, or Church of Our Lady, whose distinctive dome had dominated the Dresden skyline for two centuries.
On 13 February 1945, British and American bombers flattened the graceful city, known as 'Florence on the Elbe' in a series of brutal raids. The war was almost over; the Nazi war machine was close to collapse. But Dresden's historic city centre, of no military value and with no armaments factories, vanished.
In the decades after the war the Communist authorities rebuilt some buildings in the old town. The ruins of the Frauenkirche remained untouched: a vast pile of rubble in the city centre, officially a monument to the terrible nature of war. (Dresden's twin city is Coventry, whose cathedral was destroyed in German raids.)
Now, nearly four decades after the raid, there are computer-aided plans to reassemble the heap of rubble into a church once more at a cost of around DM160m ( pounds 65m). The church is to be ready for Dresden's eight hundredth anniversary, in 2006, in what the local bishop describes as 'a way of healing wounds'.
There have been mammoth rebuilding programmes before. The Old Town in Warsaw was rebuilt, after 1945, using the original architectural drawings. But nobody dreamt of putting the old stones back where they came from. In Dresden Humpty Dumpty is to be put together again from tens of thousands of electronically tagged, computer-logged pieces.
All across Dresden cranes dominate the skyline; there is construction work in every corner of the city. But nothing can compare with the remarkable scene on the church square where yellow-helmeted building workers swarm over the rubble. Every now and then a crane picks up a chunk of masonry and deposits it outside a large tent. The pieces are wheeled inside and photographed from all angles; the images are then stored on disk.
Elsewhere on site, workers with laptop computers on their knees enter precise descriptions of each piece of debris - the measurements, shape, colour, decorations and damage. Once all the photographic and verbal information is stored the numbered chunks are lifted by another crane into a kind of open-air warehouse. Just behind the site sit avenue upon avenue of fenced-off masonry, waiting for an architectural Second Coming.
The work of assembling the super-puzzle has already begun. Dieter Rosenkranz, the site architect, regularly inspects the progress: old drawings of the church are given coloured numbers, as the appropriate pieces are identified. With electronic labelling the impossible becomes almost easy. Seven thousand pieces have been sifted; tens of thousands more are still to come.
Occasionally key pieces are discovered. In the summer the church cross was found, scarcely damaged (it now stands propped in a corner of the tent). The cherub's-head marks the first indication that the holy of holies, the main altar, is about to be reached. Nobody knows how much of the altar has survived. It is reckoned that around one- third of the original building will be used again.
In Dresden feelings about the reconstruction remain mixed. People were worried that the cost was too great, especially at a time of such hardship. Many accepted the old rationale for leaving the ruins as a monument to human folly.
Since work began, however, the resistance has eased, not least because people have been reassured that money will come from private funds and not from public cash earmarked for schools or housing. Around DM10m has been raised, so far. The city of Dresden has pledged DM16m in the coming years - 10 per cent of the nominal cost. The appeal continues at home and abroad. There are glossy advertisements for Frauenkirche watches, at DM1,500 apiece, including a fragment of stone from the church; or you can 'adopt a stone' at DM2,500 a time. Many believe, however, that this will not be enough. The cost is said by some to be already much, much greater than DM160m. Regional and federal authorities may have to pick up the difference if the appeal fails to raise enough cash.
Meanwhile, the rebuilding of the Frauenkirche is seen by its supporters as a way of laying old ghosts, both from the Second World War and from the Communist era - when the city existed without an architectural heart.
One old man, selling souvenirs near the Frauenkirche, said: 'I was in there, on 12 February 1945, the night before the bombs. And I would just love to be able to go in there, once more.'